Well packing apparatus



Nov. 29, 1966 D. E. YOUNG ETAL 3,288,219

WELL PACKING APPARATUS Filed June 11, 1964 Harvard 1. fl /c(7 53 55[Jay/0 E. young 33 if, INVENTORS QKdM ATTO/P/VE United States Patent3,238,219 WELL PACKING APPARATUS David E. Young, Bellaire, and Howard L.McGill, Houston, Tex., assignors to Schlumberger Well SurveyingCorporation, Houston, Tex., a corporation of Texas Filed June 11, 1964,Ser. No. 374,488 8 Claims. (Cl. 166--120) This invention relates toapparatus adapted for packing-off a well bore; and, more particularly,to packers or bridge plugs which, when set in place, will be anchoredagainst hydraulic pressures acting from either direction thereon by ananchoring force proportionately related to the acting pressure.

In conducting such well-completion operations as acidizing, cementing,or fracturing, a full-opening well packer dependently coupled from atubing string is positioned at a particular depth in a cased well andthe packer set to isolate the formation interval to be treated from theremainder of the well bore thereabove. Treating fluids are then pumpeddownwardly at high pressure through the tubing and introduced into theformation being treated beneath the packer through perforationsappropriately located in the casing. In those instances where a wellhaving several producing formations is being completed, a selectivelyoperable bridge plug can be dependently coupled beneath a full-openingpacker. Such a bridge plug permits formation zones of selected length tobe packedoff for selective treatment of different formation intervalswith only a single trip into the well.

It will be appreciated that the packers and bridge plugs must be capableof withstanding high fluid pressures acting on them from eitherdirection. Furthermore, during the course of typical completionoperations, such packers and bridge plugs are usually subjected to highfluid pressures acting alternately from both above and below them. Thus,it is necessary that the packers and bridge plugs be securely anchoredagainst movement in either longitudinal direction.

Heret'ofore, mechanically actuated slip members have been typicallyemployed to anchor packing apparatus from movement in at least onedirection. Extendible anchoring members have also been developed whichare hydraulically actuated by the fluid being pumped through the tubingfor securing the apparatus from shifting.

Accordingly, it is an object of the present invention to provide new andimproved packing apparatus having hydraulically actuated wall-engagingmembers including extendible slip members, which members are pressedinto anchoring engagement with a force proportionately related to thepressure differential across the apparatus of the fluid in the well.

It is a further object of the present invention to provide new andimproved well-packing apparatus capable of being releasably anchored ina packed-off condition and resist extreme pressure differentials actingfrom either longitudinal direction.

Packing apparatus arranged in accordance with the present inventionincludes selectively operable, hydraulically actuated, wall-engagingmeans which, in response to a fluid pressure differential acting acrossthe apparatus from one longitudinal direction, presses the wall engagingmeans into anchoring engagement with a force proportionately related tothis differential. Whenever a fluid pressure differential acts acrossthe apparatus from the opposite direction, appropriately arrangedextendible slip members are further pressed into anchoring engagementwith an added force proportionately related to this latter pressuredifferential. Thus regardless of which direction a pressure differentialacts across the apparatus, the apparatus will be anchoringly securedwith an anchoring force that is proportionately related to this pressuredifferential.

The novel features of the present invention are set forth withparticularity in the appended claims. The present invention, both as toits organization and manner of operation together with further objectsand advantages thereof, may best be understood by way of illustrationand example of certain embodiments when taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a view of a typical full-bore packer and a bridge plugemploying principles of the present invention and depicted as they wouldappear in a well bore;

FIGS. 2A and 2B are detailed cross-sectional views of an embodiment ofthe bridge plug shown in FIG. 1; and

FIG 3 is a cross-sectional view taken along the lines 33 of FIG. 2.

As seen in FIG. 1, a retrievable bridge plug 10 having a fishing neck 11at its upper end is releasably connected thereby to an overshot 12 whichmay be dependently coupled as desired from either a tubing string 13directly or a tubing sub 14 suspended beneath a typical full-borepack-er 15. This releasable coupling of course allows the bridge plug 10to be set and left at a particular depth in a well bore 16 having acasing 17. Where used, the packer 15 of course may be subsequently setat any point thereabove irrespective of the length of the tubing sub 14connecting the bridge plug 10 to the packer.

Turning now to FIG, 2, the retrievable bridge plug 10 constructed inaccordance with the principles of the present invention includes arotatable tubular mandrel or body member 18 having its lower portiontelescopically arranged within and slidably engaged with a tubularhousing member 19. An annular expander member 20 having an upwardlydirected shoulder 21 at its upper end and a downwardly converging,conically shaped, surface 22 at its lower end is slidably mounted aroundthe central portion of the mandrel 18. A plurality of conventional slipmembers 23 are slidably connected to the upper end 24 of the housing 19and operatively arranged and engaged around the tapered surface 22 ofthe expander member 20. A freely swiveling annular ring 25 is looselymounted around the mandrel 18 and engaged against a downwardly directedshoulder 26 around the upper portion of the mandrel. Elastomeric packingmeans 27 mounted around the mandrel 18 between the annular ring 25 andthe upper shoulder 21 of the expander 20 are arranged to beforeshortened and expanded outwardly whenever the mandrel 18 is shifteddownwardly into the housing to one of its operative positions. Upwardshifting of the mandrel 18 to its other operative position will, ofcourse, allow the elastomeric packing means 27 to relax and return totheir normal position.

Normally engaged latch means 28 are provided to releasably latch themandrel 18 to the housing 19 and secure the mandrel from shifting fromeither of its two operative positions until the mandrel is first rotateda predetermined amount. This latch means 28 includes a conventional,normally contracted, split or expansible dizzy nut 29 disposed aroundthe mandrel 18 and arranged within an inwardly facing annular recess 30in the lower end of the housing 19. The dizzy nut 29 has internal,righthand, square threads 31 operatively arranged to thread edly engagespaced-apart sets of complementarily formed, right-hand, buttressthreads 32, 33 around the lower portion of the mandrel 18. The flatfaces of the lowermost mandrel threads 33 are directed downwardlywhereas the uppermost mandrel threads 32 have their flat faces directedupwardly in the opposite direction.

Thus, whenever the bridge plug 10 is retracted, the mandrel 18 is in itsuppermost operative position with the lower mandrel threads 33 beingthreadedly engaged by the dizzy nut 29. The mandrel 18 is of coursereleased only by a concerted application of right-hand torque and adownwardly directed force which screws the lowermost threads 33downwardly and out of engagement with the dizzy nut threads 31.Continued application of this downward force on the mandrel 18 willsubsequently bring the upper mandrel threads 32 into engagement with thethreads 31 of the dizzy nut 29. As the downwardly facing taperedsurfaces of the upper mandrel threads 32 come into contact withfthesquare threads 31 of the dizzy nut 29, however, the taperedthreadsurfaces 32 act as cams to expand the dizzy nut and-allow the threads 32to ratchet freely downwardly through the dizzy nut. Whenever the mandrel18 has reached its lowermost operative position, the dizzy nut 29 thencontracts and threadedly engages the upper mandrel threads 32. Theengagement of the upwardly directed flat faces of the upper mandrelthreads 32 with the lower faces of the dizzy nut threads 31 will ofcourse prevent the mandrel 18 from shifting upwardly relative to thehousing until the mandrel has been rotatively released.

Whenever it is desired to release the mandrel 18 from its lowermostoperative position, the mandrel is simultaneously rotated to the left asit is pulled upwardly. This concerted action will screw the uppermandrel threads 32 upwardly through the dizzy nut 29. Then, whenever theupper mandrel threads 32 have been disengaged from the dizzy nut threads31, the tapered upper faces of the lower mandrel threads 33 allow thesethreads to ratchet freely upwardly through the dizzy nut 29 in a mannersimilar to that of the previously described downward ratcheting actionof the upper threads 32. Whenever the mandrel 18 has reached its upperoperative position, the dizzy nut 29 again contracts to re-engage thedizzy nut threads 31 with the upper mandrel threads 32 to resecure themandrel and prevent it from shifting downwardly.

A central axial bore 34 extending the full length of the mandrel 18 iscapped at its upper end by the conventional fishing neck 11. Thisfishing neck 11 is arranged to cooperatively receive a conventionaltubular overshot 12 which may be dependently coupled from either afull-bore packer or a tubing string 13. Matched J-slots 35 on oppositesides of the fishing neck 11 are arranged to receive cooperativelyarranged J-pins 36 projecting radially inwardly from the overshot 12whenever the overshot is lowered over the fishing neck. After the J-pins36 enter the open upper end of the slots 35, the pins are lockinglyengaged in the closed portion of the slots by a concerted application ofleft-hand torque and a slight upward pull on the tubing 13. Conversely,the overshot 12 is selectively disengaged from the fishing neck 11 bylowering the tubing 13 slightly, torquing it to the right, and thenpulling the tubing upwardly.

Radial equalizing ports 37 are provided in the upper end of the mandrel18 to allow fluid to flow through the axial bore 34 and bypass thebridge plug as it is being shifted within a fluid-filled well bore.Fluid communication through the equalizing ports 37 is selectivelycontrolled by an annular valve member 38 which is slidably disposedaround the mandrel 18 immediately below the ports. O-rings 39-42 aroundthe inner surface of the valve 38 and outer surface of the mandrel 18fluidly seal the ports 37 whenever the equalizing valve member 38 isshifted upwardly to its closed position.

This slidable valve member 38 is cooperatively arranged to belongitudinally shifted by the running overshot 12 so that the equalizingports 37 are uncovered whenever the overshot is engaged with the fishingneck 11 and coveredwhenever the overshot is removed.

Whenever the valve member 38 is pulled upwardly, depending resilientfingers 43 around the lower end of the valve member are cammed outwardlyas they pass over an annular shoulder 44 around the index mandrel 18 andthen retracted after clearing the shoulder. The lower ends 45 of thesefingers 43 will then engage the upwardly facing portions of the annularshoulder 44 and hold the slidable valve member 38 in its uppermost orport-closed position after the overshot 12 has been removed.

A shoulder 46 projecting inwardly from the central portion of theovershot 12 is arranged to engage the upper end of valve member 38 andshift it downwardly to its open position as the overshot is beingcoupled to the fishing neck 11. Whenever the overshot 12 is removed bytorquing it to the right and picking up, a group of resilient fingers 47spaced around the lower portion of the overshot 12 have inwardlyprojecting shoulders 48 which engage a shoulder 49 On the sliding valvemember 38 to pull it upwardly and close the equalizing ports 37.

Whenever it is desired to move the bridge plug 10, the overshot 12 isdropped over and re-engaged with the fishing neck 11. Once the overshot12 reaches its engaging position, J-pins 36 will reenter the open upperend of the J-slots 35 on the fishing neck 11. As the J-pins 36 reenterthe closed portion of the slots, the slidable valve member 38 is againshifted downwardly to reopen the equalizing ports 37.

A hydraulically actuated, radially expansible, friction anchor 50 ismounted around the housing 19 and adapted to be pressed outwardlyagainst the casing to initially secure the housing relatively fixedagainst rotation of the mandrel 18 as well as to subsequently anchor thebridge plug 10 against a pressure differential acting upwardly againstthe bridge plug.

This anchor assembly 50 includes an elastomeric sleeve 51 encircling thehousing 19 with a plurality of elongated casing-contacting members 52,53 being uniformly mounted around the periphery of this sleeve. Theupper 54 and lower 55 ends of the elastomeric sleeve 51 are enlarged andsealingly secured within opposed annular recesses 56, 57 around thehousing 19 to provide an annular fluid-tight space 58 between the sleeveand housing.

Each of the casing-engaging members 52, 53 are elongated and have athick, arcuate, cross-section (FIG. 3). Alternate ones 52 of thesecasing-engaging members are centrally aligned and mounted along theouter convex surface of relatively thin, elongated, arcuate backingmembers 59. These mounted members 52 are arranged uniformly around theperiphery of the elastomeric sleeve 51 so that the backing members 59substantially encompass the sleeve. The unmounted casing-engagingmembers 53 are alternately disposed between the mounted casingengagingmembers 52 in such a manner that the unmounted members 53 straddleadjacent backing members 59 and cover the gap 60 therebetween. The endsof the casingengaging members 52, 53 are loosely disposed within theopposed annular recesses 56, 57 around the housing 19 at opposite endsof the members.

Turning now to the hydraulic system of the present invention, anelongated annular space having an enlarged cross-sectional upper portion61 and a reduced crosssectional lower portion 62 is formed in thehousing 19 above the anchor 50. An annular piston member 63 is slidablydisposed within the annular space with an enlarged upper portion 64 anda smaller portion 65 thereof, respectively, being complementarily fittedwithin the upper 61 and lower 62 annular spaces. A compression spring 66engaged between the housing 19 and the enlarged portion 64 of the pistonmember 63 biases the piston downwardly into the lower annular space 62.

O-rings 67, 68 around the outer and inner surfaces of the enlargedpiston port-ion 64 and an O-ring 69 around the inner surface of thereduced piston portion 65 fluidly seal the annular piston member 63relative to the housing 19. The O-rings 67-69 accordingly form andseparate a lower fluid-tight chamber 7 9 beneath the reduced pistonportion 65; an intermediate fluid-tight chamber 71 between the enlargedpiston portion 64 and the lower enlarged piston portion 64.

A fluid passage 73 leading from the lower chamber 70 provides fluidcommunication therefrom to the annular fluid-tight space 58 beneath theelastomeric sleeve 5-1 of the anchor 50. The fluid-tight space 58, fluidpassage 73 and the lower chamber 70 are filled with a suitable hydraulicfluid. It will be appreciated, of course, that whenever the annularpiston member 63 is shifted downwardly into the lower fluid-tightchamber 70, a hydraulic pressure will be accordingly developed to expandthe elastomeric sleeve 51 and press the casing-engaging members 52, 53against the casing. Thus, the downwardly directed biasing force of thecompression spring 66 against the piston 63 will develop a slighthydraulic pressure sufiicient to maintain the casing-engaging members52, 53 against the casing. The members 52, 53 are pressed with onlysufficient force to secure the housing 19 against moving relative to themandrel 18 but not so great as to retard shifting of the bridge plug 10.

It will be realized that annular piston member 63 will be shifted eitherdownward-1y or upwardly relative to the housing 19 in response toditferences between the fluid pressures in the upper 72 and intermediate71 fluid-tight chambers and the cross-sectional areas of the uppersurface and the lower surface of the enlarged piston portion 64. Thedirection that the piston member 63 shifts will of course be determinedby the relative difference between the arithmetical product of the fluidpressure in each chamber and the effective area of the piston surface inthat chamber. Accordingly, to actuate the piston member 63 a fluidpassage 74 is formed through the housing 19 at a point beneath thepacking means 27 to provide fluid communication therefrom to the upperfluid-tight chamber 72. An elongated fluid passage 75 through themandrel 18 provides fluid communication from a point above the packingmeans 27 to the intermediate fluidtight chamber. Thus, whenever thepacking means 27 is sealingly engaged within a fluid-filled well bore,the pressure of the fluids above the bridge plug will be directedthrough the fluid passage 75 into the intermediate chamber 71 to actagainst the lower surface of the enlarged piston portion 64. At the sametime, the fluid pressure in the well below the bridge plug 10 will beapplied against the upper surface of the enlarged piston portion 64through fluid passage 74.

The hydraulic system of the present invention further includes anelongated, inwardly facing, annular space 76 wtihin the expander memberinto which anannular shoulder 77 around the central portion of themandrel 18 is received. An O-ring 78 fluidly seals the lower portion ofthe expander 20 below the annular space 76 to the mandrel 18. Similarly,an O-ring 79 around the mandrel shoulder 77 fluidly seal-s the mandrel18 relative to the upper portion of the expander member 20 above theannular space 76 to make it a fluid-tight chamber. A radial port 80extending through the mandrel 18 into the elongated fluid passage 75provides fluid communication from a point above the packing means 27 tothe fluidtight chamber 76. A second port 81 through the expander member20 above the O-ring 79 around the mandrel shoulder 77 provides fluidcommunication from the exterior of the bridge plug 10 below the packingmeans 27 to the upper face 82 of the shoulder 77.

It will be appreciated, therefore, that with the bridge plug 10 inposition within a fluid-filled well bore, whenever the packing means 27is sealingly engaged therein, the well bore pressure above the packingmeans will be simultaneously directed into both the fluid-tight chamber76 within the expander member 20 and the intermediate fluid-tightchamber 71 within the housing 19. At the same time, whatever fluidpressure there is in the well bore below the sealingly engaged packingmeans 27 will be imposed into the upper fluid-tight chamber 72 in thehousing 19 above the annular piston member 63 as well as through theport 81 against the upper face of mandrel shoulder 77 As previouslydescribed, whenever the bridge plug 10 has been positioned in the wellbore, the casing-engaging members 52, 53 act as drag blocks to securethe housing 19 from moving as the mandrel 18 is manipulated to set thebridge plug. The tubing string 13 is lowered slightly as it is rotatedto the right. This action successively rotates the J-pins 36 of theovershot 12 into the bottom of the open portion of the fishing neckJ-slots 35 and screws the lower mandrel threads 33 out of the dizzy nut29. As the mandrel 18 travels downwardly, force is transmitted from theupper mandrel shoulder 26 through the packing means 27 and against theupper face 21 of the expander 20 to shift the expander downwardlyrelative to the housing 19.

As the expander member 20 moves downwardly relative to the housing 19,the tapered expander surface 22 of course forces the slip members 23outwardly into engagement with the casing. Once the slip members 23 areengaged, the expander 20 cannot move further downwardly; and thecontinued downward travel of the upper mandrel shoulder 26 will thenbegin foreshortening the packing means 27 into sealing engagement.

The mandrel 18 will of course continue to travel downwardly until thepacking means 27 are sealingly engaged and the slip members 23 set. Theupper mandrel threads 32 will ratchet through the dizzy nut 29 until themandrel 18 reaches its lower operative position. Then, the dizzy nut 29will contract to engage the mandrel threads 32 and secure the mandrel 18as previously described.

Once the mandrel 18 is secured, the overshot 12 may then be pulledupwardly and released from the fishing neck 11. As the overshot 12 ispulled upwardly, the sliding valve member 38 is shifted upwardly toclose the equalizing ports 37 as previously described. Accordingly, assoon as the overshot 12 has been removed and the equalizing ports 37closed, whatever pressure differential there is across the packing means27 will be imposed against the anchoringly and sealingly engaged bridgeplug 10.

It will be realized that should the pressure in the well bore above thebridge plug 10 be greater than'that below, the resulting pressuredifferential across the bridge plug will impose a downwardly directedforce against the mandrel 18. Since, however, the annular ring 25 abovethe packing means 27 is not fluidly sealed against the uppermost mandrelshoulder 26, the same pressure will act on both faces of the shoulder.Thus, the pressure on the mandrel 18 will in effect be acting downwardlyonly against the cross-sectional area of that portion of the mandrelthat is encompassed by and extends through the packing means 27.

This resultant downward pressure force on the mandrel 18 issubstantially counteracted, however, inasmuch as the same higherpressure that is acting downwardly is also transmitted through theelongated fluid passage 75 in the mandrel and acts upwardly against thelower face of the mandrel shoulder 77 within the fluid tight chamber 76in the expander 20. It will be appreciated, therefore, that byappropriately dimensioning the shoulder 77, its effective annularcross-sectional area can be made substantially equal to, or evenslightly greater than the above-mentioned effective cross-sectional areaof the mandrel 18. Thus, no significant pressure forces will be applieddownwardly on the mandrel 18, which forces would otherwise betransmitted from the upper mandrel threads 32 into the dizzy nut threads31.

This same higher pressure above the packing means 27 is of courseimposed against the full cross-sectional area of the upper end of thepacking means 27 to aid in maintaining the packing means sealinglyengaged with the casing. This downwardly directed force is alsotransmitted through the elastomeric packing means 27 against the upperend 21 of the expander 20. In addition to this force being appliedthrough the packing means 27, the higher pressure acting on the lowersurface of the chamber 76 within the expander 20 will impose anadditional downwardly acting force on the expander. Thus, a substantialadditional downwardly acting force will be directed against the expander20 to maintain the slip members 23 anchoringly engaged with the casingwhenever there is a greater pressure above the bridge plug 10 than thatbelow it.

It will be realized, of course, that with the well bore pressure beinggreater above the packing means 27 than that therebelow, annular pistonmember 63 will be shifted upwardly against the spring 66 in the upperend of the upper housing chamber 72. Thus, there will be little or nohydraulic pressure in the hydraulic system of the anchor 50.

Should, perchance, the pressure in the well bore below the sealinglyengaged packing means 27 be or become greater than that thereabove, themandrel 18 will of course be restrained from moving relative to thehousing 19 by the engagement of the upper mandrel threads 32 with thoseof the dizzy nut 29. It will be appreciated, of course, that with ahigher pressure below the bridge plug 10, the slip members 23 will notetfectively secure the bridge plug 10 against shifting upwardly and theanchor 50 must now act to secure the bridge plug.

Accordingly, the higher pressure beneath the sealingly engaged packingmeans 27 will now be imposed against the upper face of the enlargedportion 64 of the annular piston member 63 by way of fluid passage 74.The annular piston member 63 will now be forced downwardly to develop ahydraulic pressure within the lower fluidtight chamber 70. It will berecognized that this developed hydraulic pressure will beproportionately greater than the pressure in the well bore beneath thepacking means 27 by a ratio equal to the effective cross-sectional areaof the enlarged piston portion 64 divided by the effectivecross-sectional area of the reduced piston portion 65. Thus, since thesame pressure is acting on the outside of the elastomeric sleeve 51 asthat acting on the upper end of the annular piston member 63, theincreased hydraulic pressure within the fluid-tight chamber 70 willexpand the elastomeric sleeve outwardly to press the casing-engagingmembers 52, 53 tightly against the casing and secure the bridge plug 10against shifting with a force proportionately related to the pressurediiferential across the bridge plug.

The mandrel 18 is still eifectively balanced inasmuch as the higherpressure now enters the fluid port 81 and imposes a downwardly directedforce on the upper face of mandrel shoulder 77. The resulting downwardforce will of course oppose the upwardly directed pressure force againstthe effective cross-sectional area of the mandrel 18 in the same manneras previously described.

Thus, it will be realized that the bridge plug 10 will be securelyanchored against longitudinal shifting in either direction inasmuch asthe slip members 23 secure the bridge plug from shifting downwardly whenthere is a higher pressure thereabove. Correspondingly, the anchor 50secures the bridge plug 10 from upward shifting whenever the pressurebeneath the bridge plug is greater than that above.

Accordingly, it will be appreciated that the present invention providesnew and improved packing apparatus having hydraulically actuatedwall-engaging members. These members are arranged to be pressed intoanchoring engagement with the well casing with a force proportionatelyrelated to a pressure differential acting across the packing apparatus.Furthermore, this new and improved Well-packing apparatus is capable ofbeing releasably anchored in a packed-off condition to resist extremepressure differentials acting from either longitudinal direction.

While particular embodiments of the present invention have been shownand described, it is apparent that changes and modifications may be madewithout departing from this invention in its broader aspects and,therefore, the aim in the appended claims is to cover all such changesand modifications as fall within the true spirit and scope of thisinvention.

What is claimed is: 1. A Well packer sized and adapted for reception ina well bore for packing-01f the well bore comprising:

a housing having a longitudinal bore;

a body member slidably disposed within said housing bore;

packaging means operatively mounted on said body member and arranged forexpansion thereby into sealing engagement with the well bore;

first anchoring means selectively operable for securing said packeragainst longitudinal movement in one direction within the well bore;

second anchoring means for securing said packer against longitudinalmovement in the opposite direction relative to the well bore includingoutwardlyextendible wall-engaging means mounted on said housing andfluidly sealed relative thereto to provide a fluid-tight spacetherebetween, said wall-engaging means being adapted for extension intoengagement with the well bore upon application of hydraulic pressure insaid fluid-tight space; and

hydraulic means responsive to a pressure differential acting in saidopposite direction across said packing means when expanded for applyinga hydraulic pressure in said fluid-tight space to press saidwall-engaging means into anchoring engagement with a forceproportionately related to this pressure differential.

2. A well packer sized and adapted for reception in a well bore forpacking-off the well bore comprising:

a housing having a longitudinal bore;

a body member having a fixed shoulder, said body member being slidablydisposed within said housing bore and adapted for travel therein from afirst position to a second position;

first anchoring means responsive to travel of said body member forsecuring said packer against longitudinal movement in one directionrelative to the well bore whenever said body member is in said secondposition including outwardly-extendible wall-engaging slip members andexpander means operatively engaged with said slip members;

packing means mounted around said body member intermediate said fixedshoulder and first anchoring means and operatively arranged forexpansion into sealing engagement with the well bore whenever said bodymember is shifted into said second position;

means for securing said body member to said housing Whenever said bodymember is in said second position;

second anchoring means for securing said packer against longitudinalmovement in the opposite direction, relative to the well bore includingoutwardlyextendible wall-engaging means mounted on said housing andfluidly sealed relative thereto to provide a fluid-tight spacetherebetween, said wallengag 1ng means being adapted for extension intoengagement with the well bore upon application of hydraulic pressure insaid fluid-tight space; and

hydraulic means responsive to a pressure differential acting in saidopposite direction across said packing means when expanded for applyinga hydraulic pressure in said fluid-tight space to press saidwall-engaging means into anchoring engagement with a forceproportionately related to this pressure diiferential.

3. A well packer sized and adapted for reception in a well bore forpacking-off the well bore comprising:

a housing having a longitudinal bore and a chamber therein;

a body member having a fixed shoulder, said body member being slidablydisposed within said housing bore and adapted for travel therein from afirst position to a second position;

first anchoring means responsive to travel of said body member forsecuring said packer against longitudinal movement in one directionrelative to the well bore whenever said body member is in said secondposition including outwardly-extendible wall-engaging slip members andexpander means operatively engaged with said slip members;

packing means mounted around said body member intermediate said fixedshoulder and first anchoring means and operatively arranged forexpansion into sealing engagement with the well bore Whenever said bodymember is shifted into said second position;

means for securing said body member to said housing whenever said bodymember is in said second position;

second anchoring means for securing said packer against longitudinalmovement in the opposite direction relative to the well bore includingoutwardly-extendible wall-engaging means mounted on said said housingand fluidly sealed relative thereto to provide a fluid-tight spacetherebetween, said Wallengaging means being adapted for extension intoengagement With the well bore upon application of hydraulic pressure insaid fluid-tight space; and

hydraulic means responsive to a pressure differential acting in saidopposite direction across said packing means when expanded for applyinga hydraulic pressure in said fluid-tight space to pressure saidwallengaging means into anchoring engagement with a forceproportionately related to this pressure differential including a pistonmember slidably disposed within said housing chamber and adapted toshift therein in response to this pressure differential;

means fluidly sealing said piston member within said chamber for fluidlyisolating a portion of said chamber;

first passage means providing fluid communication between said isolatedchamber portion and said fluidtight space, all being filled with ahydraulic fluid; and second passagev means providing fluid communicationbetween the well bore and the other portion of said chamber.

4. A well packer sized and adapted for reception in a well borecomprising:

a housing having a longitudinal bore and a cylindrical chamber therein,said chamber having a first portion of a greater cross-sectional areathan the remaining portion of said chamber;

a body member having a fixed shoulder, said body member being slidablydisposed within said housing bore and adapted for travel therein from afirst position to a second position;

first anchoring means responsive to travel of said body member securingsaid packer against longitudinal movement in one direction relative tothe well bore Whenever said body member is in said second positionincluding outwardly-extendible wall-engaging slip members mounted onsaid housing and expander means slidably mounted on said body member andoperatively engaged with said slip members;

packing means mounted around said body member intermediate said fixedshoulder and expander means and operatively arranged for expansion intosealing engagement with the well bore Whenever said body member isshifted into said second position;

means for securing said body member to said housing whenever said bodymember is in said second posi tion;

second anchoring means for securing said packer against longitudinalmovement in the opposite direction relative to the well bore includingoutwardlycxtendible Wall-engaging means mounted on said housing andfluidly sealed relative thereto to provide a fluid-tight spacetherebetween, said wall-engaging means being adapted for extension intoengagement with the well bore upon application of hydraulic pressure insaid fluid-tight space; and

hydraulic means responsive to a pressure differential acting in saidopposite direction across said packing means when expanded for applyinga hydraulic pressure in said fluid-tight space to press saidwall-engaging means into anchoring engagement with a forceproportionately related to this pressure diflerential including a pistonmember having an enlarged portion and a reduced portion complementarilyfitted and slidably disposed within said housing chamber and adapted toshift therein in response to this pressure differential;

first and second sealing means respectively fluidly sealing said pistonportions for dividing said first chamber portion and isolating saidremaining chamber portion from said divided portions;

first passage means providing fluid communication between said isolatedchamber portion and said fluidtight space, all being filled with ahydraulic fluid;

second passage means providing fluid communication from the well boreabove said packing means to one of said divided chamber portions; and

third passage means providing fluid communication from the well borebelow said packing means to the other of said divided chamber portions.

5. A well packer sized and adapted for reception in a well bore forpacking-off the well bore comprising:

a housing having a longitudinal bore;

a body member slidably disposed within said housing bore;

packing means operatively mounted on said body member and arranged forexpansion into sealing engagement with the well bore;

first anchoring means responsive to a pressure differential acting inone direction across said packing means when expanded for securing saidpacker against 1ongitudinal movement in said one direction within thewell bore;

second anchoring mean for securing said packer against longitudinalmovement in the opposite direction relative to the well bore includingoutwardly-extendible Wall-engaging means mounted on said housing andfluidly sealed relative thereto to provide a fluid-tight spacetherebetween, said wall-engaging means being adapted for extension intoengagement with the well bore upon application of hydraulic pressure insaid fluid-tight space; and

hydraulic means responsive to a pressure differential acting in saidopposite direction across said packing means when expanded for applyinga hydraulic pressure in said fluid-tight space to press saidwallengaging means into anchoring engagement with a forceproportionately related to this pressure differential.

6. A well packer sized and adapted for reception in a well bore forpacking-off the well bore comprising:

a housing having a longitudinal bore;

a body member having a fixed shoulder 51d an enlarged diameter portionlongitudinally spaced from said shoulder, said body member beingslidably disposed Within said housing bore and adapted for traveltherein from a first position to a second position;

first anchoring'means responsive to travel of said body member forsecuring said packer against longitudinal movement in one directionrelative to the well bore Whenever said body member is in aid secondposition including outwardly-extendible wall-engaging slip membersmovably mounted on said housing and an annular slip cone having anenlarged bore portion slidably mounted around said enlarged body portionand operatively engaged with said slip members;

packing means mounted around said body member intermediate said fixedshoulder and slip cone and operatively arranged for expansion intosealing engagement with the well bore whenever said body member isshifted into said second position;

means for securing said body member to said housing whenever said bodymember is in said second posi tion;

first hydraulic means responsive to a pressure differential acting insaid one direction across said packing means when expanded for urgingsaid slip cone against said slip members with an additional forceproportionately related to this pressure differential;

second anchoring means for securing said packer against longitudinalmovement in the opposite direction relative to the well bore includingoutwardly-extendible wall-engaging means mounted on said housing andfluidly sealed relative thereto to provide a fluid-tight spacetherebetween, said wall-engaging means being adapted for extension intoengagement with the well bore upon application of hydraulic pressure insaid fluid-tight space; and

second hydraulic means responsive to a pressure differential acting insaid opposite direction across said packing means when expanded forapplying a hydra-ulic pressure in said fluid-tight space to press saidwall-engaging means into anchoring engagement with a forceproportionately related to this pressure differential.

7. A well packer sized and adapted for reception in a well bore forpacking-off the well bore comprising:

a housing having a longitudinal bore and Ya chamber therein;

a body member having a fixed shoulder and an enlarged diameter portionlongitudinally spaced from said shoulder, said body member beingslidably disposed within said housing bore and adapted for traveltherein from a first position to a second position;

first anchoring means responsive to travel of said body member forsecuring said packer against longitudinal movement in one directionrelative to the well bore whenever said body member is in said secondposition including outwardly-extendible wall-engaging slip membersmovably mounted on said housing and an annular slip cone having anenlarged bore portion slidably mounted around said enlarged body portionand operatively engaged wit-h said slip members;

packing means mounted around said body member intermediate said fixedshoulder and slip cone and operatively arranged for expansion intosealing engagement with the well bore whenever said body member isshifted into said second position;

means for securing said body member to said housing whenever said bodymember is in said second position;

first hydraulic means responsive to a pressure differential acting insaid one direction across said packing means when expanded for urgingsaid slip cone against said slip members with an additional forceproportionately related to this pressure differential including firstand second means respectively fluidly sealing said enlarged body portionwithin said enlarged bore portion and said body member to said slip coneto provide a fluid-tight chamber in said enlarged bore portion betweensaid sealing means, and first passage means providing fluidcommunication between said fluid-tight chamber and the well bore at apoint longitudinally displaced in the opposite direction from saidpacking means;

second anchoring means for securing said packer against longitudinalmovement in said opposite direction relative to the well bore includingoutwardly-extendible wall-engaging means mounted on said housing andfluidly sealed relative thereto to provide a fluid-tight spacetherebetween, said wall-engaging means being adapted for extension intoengagement with the well bore upon application of hydraulic pressure insaid fluid-tight space; and

second hydraulic means responsive to a pressure differential acting insaid opposite direction across said packing means when expanded forapplying a hydraulic pressure in said fluid-tight space to press saidwall-engaging means into anchoring engagement with a forceproportionately related to this pressure differential including a pistonmember slidably disposed within said housing chamber and adapted toshift therein in response to this pressure differential;

third means fluidly sealing said piston member Within said chamber forfluidly isolating a portion of said chamber;

second passage means providing fluid communication between said isolatedchamber portion and said fluidtight space, all being filled with ahydraulic fluid; and third passage means providing fluid communicationbetween the well bore at a point longitudinally displaced in said onedirection from said packing means and the other portion of said chamber.

8. A well packer sized and adapted for reception in a well borecomprising:

a housing having a longitudinal bore and a cylindrical chamber therein,said chamber having a first portion of a greater cross-sectional areathan the remaining portion of said chamber;

a body member having a fixed shoulder and an enlarged diameter portionlongitudinally spaced from said shoulder, said body member beingslidably disposed within said housing bore and adapted for traveltherein from a first position to a second position;

first anchoring means responsive to travel of said body member forsecuring said packer against longitudinal movement in one directionrelative to the well bore whenever said body member is in said secondposition including outwardly-extendible wall-engaging slip membersmovably mounted on said housing and an annular slip cone having anenlarged bore portion slidably mounted around said enlarged body portionand operatively engaged with said slip members;

packing means mounted around said body member intermediate said fixedshoulder and slip cone and operatively arranged for expansion intosealing engagement with the well bore whenever said body member isshifted into said second position;

means for securing said body member to said housing whenever said bodymember is in said second position;

first hydraulic means responsive to a pressure differential acting insaid one direction across said packing means when expanded for urgingsaid slip cone against said slip members with an additional forceproportionately related to this pressure differential;

including first and second means respectively fluidly sealing saidenlarged body portion within said enlarged bore portion and said bodymember to said slip cone to provide a fluid-tight chamber in saidenlarged bore portion between said sealing means, and first passagemeans providing fluid communication between said fluid-tight chamber andthe well bore at a point longitudinally displaced in the oppositedirection from said packing means;

second anchoring means for securing said packer against longitudinalmovement in the opposite direction relative to the well bore includingoutwardly-extendible wall-engaging means mounted on said housing andfluidly sealed relative thereto to provide a fluid-tight spacetherebetween, said wall-engaging means being adapted for extension intoengagement with the well bore upon application of hydraulic pressure insaid fluid-tight space;

second hydraulic means responsive to a pressure differential acting insaid opposite direction across said packing means when expanded forapplying a hydraulic pressure in said fluid-tight space to press saidwail-engaging means into anchoring engagement with a forceproportionately related to this pressure differential including a pistonmember having an enlarged portion and a reduced portioncomplement-tu'ily fitted and slidably disposed within said housingchamber and adapted to shift therein in response to this pressuredifferential;

third and fourth sealing means respectively fluidly sealing said pistonportions for dividing said first chamber portion and isolating saidremaining chamber portion from said divided portions;

second passage means providing fluid communication between said isolatedchamber portion and said fluidtight space, all being filled with ahydraulic fluid;

third passage means providing fluid communication from the well boreabove said packing means to one of said divided chamber portions; and

fourth passage means providing fluid communication from the well borebelow said packing means to the other of said divided chamber portions.

References Cited by the Examiner UNITED STATES PATENTS CHARLES E.OCONNELL, Primary Examiner.

D. H. BROWN, Assistant Examiner.

